The oldest television commercial is a 10-second spot for Bulova watches, which aired on July 1, 1941, in the United States, before a baseball game between the Brooklyn Dodgers and the Philadelphia Phillies. The ad, which cost between $4 and $9, was broadcast on WNBT (now WNBC) in New York. It featured a modified WNBT test pattern resembling a clock with the Bulova logo and the phrase "Bulova Watch Time".

Here's a breakdown:

Brand: Bulova Watch Company.
Date: July 1, 1941.
Location: WNBT (now WNBC) in New York.
Duration: 10 seconds.
Cost: $4 to $9 (reports vary).
Content: Modified WNBT test pattern resembling a clock with the Bulova logo.
Audience: An estimated 4,000 viewers in New York.
Significance: Marked the beginning of television advertising.